714 research outputs found

    FP-tree and COFI Based Approach for Mining of Multiple Level Association Rules in Large Databases

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    In recent years, discovery of association rules among itemsets in a large database has been described as an important database-mining problem. The problem of discovering association rules has received considerable research attention and several algorithms for mining frequent itemsets have been developed. Many algorithms have been proposed to discover rules at single concept level. However, mining association rules at multiple concept levels may lead to the discovery of more specific and concrete knowledge from data. The discovery of multiple level association rules is very much useful in many applications. In most of the studies for multiple level association rule mining, the database is scanned repeatedly which affects the efficiency of mining process. In this research paper, a new method for discovering multilevel association rules is proposed. It is based on FP-tree structure and uses cooccurrence frequent item tree to find frequent items in multilevel concept hierarchy.Comment: Pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS, Vol. 7 No. 2, February 2010, USA. ISSN 1947 5500, http://sites.google.com/site/ijcsis

    Sufficient Conditions for Starlike Functions Associated with the Lemniscate of Bernoulli

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    Let -1\leq B<A\leq 1. Condition on \beta, is determined so that 1+\beta zp'(z)/p^k(z)\prec(1+Az)/(1+Bz)\;(-1<k\leq3) implies p(z)\prec \sqrt{1+z}. Similarly, condition on \beta is determined so that 1+\beta zp'(z)/p^n(z) or p(z)+\beta zp'(z)/p^n(z)\prec\sqrt{1+z}\;(n=0, 1, 2) implies p(z)\prec(1+Az)/(1+Bz) or \sqrt{1+z}. In addition to that condition on \beta is derived so that p(z)\prec(1+Az)/(1+Bz) when p(z)+\beta zp'(z)/p(z)\prec\sqrt{1+z}. Few more problems of the similar flavor are also considered

    Alkali treatment of Ti6Al4V alloy and it’s effect on bio-activity

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    The purpose of this work was to investigate the bone-like apatite inducement ability of alkali and heat treated Ti-6Al-4V alloy in the HANK solution, with variation of concentration of NaOH solution and heat treatment temperature. The characterization techniques such as Scanning electron microscopy (SEM), X-ray diffraction (XRD), were selected for the evaluation of chemical composition, morphological and crystallinity properties of alkali and subsequent heat treated Ti-6Al-4V alloy. From the XRD analysis it was found that the hydroxyapatite inducement ability increased with the increments of treating temperature, while reduced with increments of concentration

    Effect of axial dispersion on interphase mass transfer in packed absorption columns

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    A steady state approach was followed in this investigation to determine the effects of liquid and gas flow rates, packing size and packing height on the interphase mass transfer coefficient and gas phase axial mixing Peclet numbers. Experiments were performed on the absorption of carbon dioxide from a mixture of carbon dioxide and nitrogen in a packed column. Absorption was performed using 1/4, 3/8 and l/2 inch Raschig rings, with a packing height of 3 feet and also using 3/8 inch Raschig rings with a packing height of 5 feet. The liquid and gas flow ranges used were 2865 to 5680 lb./hr.sq.ft. and 5.0 to 7.4 lb./hr.sq.ft respectively. Three mathematical models, viz. (i) plug flow in both the gas and liquid phases, (ii) axial mixing in gas phase and plug flow in liquid phase, and (iii) axial mixing in both gas and liquid phases, were used. It is found that axial mixing in the gas phase increases with increases in liquid flow rate, packing size and packing height. The behavior of apparent and true mass transfer coefficients indicates a decrease in axial mixing with increases in gas flow rates. However, axial mixing is found to be small under the experimental conditions used in this investigation. The gas phase Peclet numbers obtained in this investigation are about fifty times greater than reported by workers using a transient technique under the same conditions. Correlations for the apparent and true over-all liquid phase mass transfer coefficients are also presented --Abstract, page ii

    Fundamentals of Natural Dyes and Its Application on Textile Substrates

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    The meticulous environmental standards in textiles and garments imposed by countries cautious about nature and health protection are reviving interest in the application of natural dyes in dyeing of textile materials. The toxic and allergic reactions of synthetic dyes are compelling the people to think about natural dyes. Natural dyes are renewable source of colouring materials. Besides textiles it has application in colouration of foods, medicine and in handicraft items. Though natural dyes are ecofriendly, protective to skin and pleasing colour to eyes, they are having very poor bonding with textile fibre materials, which necessitate mordanting with metallic mordants, some of which are not eco friendly, for fixation of natural dyes on textile fibres. So the supremacy of natural dyes is somewhat subdued. This necessitates newer research on application of natural dyes on different natural fibres for completely eco friendly textiles. The fundamentals of natural dyes chemistry and some of the important research work are therefore discussed in this review article

    Design, construction and operation of equipment for the study of evaporation of aqueous solutions using a simplified reactor design approach

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    The study of simultaneous heat and mass transfer in flow reactors has attracted the attention of many workers for a long time due to its wide application in the industrial field. These heat and mass transfer studies play an important role in determining the rate equations and in turn the size of the reactor itself. A large number of chemical reactions have been studied by various workers…. The purpose of this work comprised only the initial or exploratory phase of this overall project, and deals with the design, construction and assembling of the equipment necessary to carry out the vaporization of pure water in a reactor on a continuous and steady state basis. Further, the purpose of this work was to demonstrate that the necessary temperatures could be successfully measured and flow rates determined accurately enough to calculate the per cent water evaporated for different flow rates of water at fixed initial gas temperatures. No attempt has been made at this stage of the investigation to propose any rate equation for the process of evaporation of water in a gas stream under given conditions as this phase of the work is planned to be covered in a future thesis --Introduction, pages 1-2

    A permeability scaling technique in the numerical simulation of water coning

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    A two-dimensional, two-phase, radial, horizontally layered water coning simulator was programmed for large memory digital computers. A permeability sealing technique is developed which allows the use of large size blocks as production blocks. As a result of this technique large time steps have been used without causing saturation instabilities around the well bore and the permeability scaling technique allows a more realistic simulation of a water cone. The IMPES method is used to calculate pressure and saturation in the system for each finite time step. The behaviour of the simulator is studied for various factors affecting the advance of a water cone in a reservoir --Abstract, page ii

    IDENTIFICATION OF CRITICAL FACTORS FOR DELAY IN METRO RAIL PROJECTS IN INDIA

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    Purpose of the study:World over, transportation infrastructure projects face delays in commissioning and India is no exception. This study is carried out with an objective to specifically identify the critical delay factors in the commissioning of metro rail projects in India. Methodology: A questionnaire survey was conducted to identify the major causes of delay from the opinion of clients, contractors and consultants. Calculation of Relative Importance Index (RII) for the shortlisted factors yielded the ranking. The ranking by various categories of respondents was analysed using Spearman’s rank coefficient. Main Findings:The study concluded in identification of 10 most critical delay-factors from a list of 49 shortlisted factors spread across 7 categories. The identified factors included: (1) Delay in land acquisition and site handover to contractor, (2) Shifting of utilities and contingency works, (3) Scope change, (4)Delay in payments, (5) Effects of unforeseen subsurface and changing ground condition, (6) Shortage of construction materials in the market, (7) Delays in design approvals and decision making, (8) Shortage of labour, (9) Lack of data collection and survey before design, and (10) Delay in obtaining permits from local body. Implications: Project management interventions based on the identified critical factors of delay can improve the delivery of upcoming metro rail projects in terms of schedule compliance. Applications of this study:The Application of suitable course correction measures targeting the critical factors can result in mitigation of delays. Novelty/Originality of this study:The study is one of its kind attempt to investigate all the commissioned metro rail projects in India for analyzing delays in the Indian urban rail sector
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